Inclosed-arc lamp.



Patented Dec. 10, 1918.

2 SHEETS-SHEET I.

T. SPENCER.

INCLOSED ARC LAMP.

APPucATloN FILED MN. 17.1915

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INVEITORI' l Wym.

Patented Dec.' 10, 1918.

' 2 SHEETS-SHEET 2- T. SPENCER.

INCLOSED AHC LAMP.

APPucATloN FILED 1AN.17. |913.

W IT N ES S ES:

faq J g @@fi UNITED sTATEs PATENT oEEIoE.

`THOMAS SPENCER, F PHILADELPHIA, PENN SYLvANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO NATIOILAL CARBON COMPANY, INC., 0F CLEVELAND, OHIO, A CORPO'- 'EATIoN or NEW Yonx.

INCLOSED-ARC LAMP.

Specication of L'etters Patent.v Patented De@- 10 1918.

Application mea January 17, 191s. ser-1am. i4as5o.

To all whom z't may concern:

Be it known that I, THOMAS SPENCER, of Philadelphia, in the State of Pennsylvania, have invented a certain new and useful Improvement in Inclosed-Arc Lamps, whereof the following is a specification, reference being had to the accompanying drawings.

My invention may be employed with p articular advantage in lamps of Vthe flammg arc type. Such lamps rapidly depreclate 1n luminosity during operation because the products of combustion condense, as a semiopaque film, upon the inner surface of the globe forming the immediate arc mclosure and restrict the transmission of light therethrough. I have discovered that the deposit of said obscuring film upon the inner globe is dependent upon the temperatnrepf the latter, and that if said globe 1s mamtained at a temperature sufficiently high the products of combustion are not deposlted thereon. Therefore, the principal object of my present invention is to provide an' in .Closed arc lam with means which during the operation o the lamp maintain the inner globe at a temperature sufficiently high to minimize and substantially prevent the obscuration of the inner globe by the deposit of the products of internal combustion thereon.

As hereinafter described my invention includes an inner globe which is the immediate inclosure of the arc; an outer globe surrounding said inner globe in closely spaced relation therewith so constructed and arranged as to hold a substantially confined layer of hot air around said inner globe exterior to the latter. Moreover, my invention includes means whereby all of the members of the lamp, which require cleaning, including said two globes, are held securely in cooperative relation but may be readily separated and reassembled with the minimum amount of manipulation.

My invention includes the various novel features of construction and arrangement hereinafter more definitely specified.

Figure I is a vertical section of the lower part of a lamp made in accordance with my invention Fig. II is a sectional view similar to Fig. I but showing the separable members disassembled.

The frame is provided with the casing 7 for the lamp governing mechanism and has at the bottom thereof the base plate 9 hav- -ing the upwardly extending` flange 10 for engagement with said casing 7. Said base plate 9 1s provided with the central bushing 12, through which the upper carbon 14 extends, and supports the tubes 15 through which extend the slide rods 16 of the holder 17 of the lower carbon 18. The downwardly extending cylindrical portion 20 of said base plate 9 is provided at the bottom thereof w1th the two annular flanges 21 and 22, having the double conical or V-shaped annular groove 24 between them for tight engagement with the similarly inclined double conical flange 25 on the canopy'frame 26 7(' which supports the canopy 28.

Sa1d canopy frame 26 has the vertically extending annular baille flange 30 in concentr1c relation with said carbons 14 and 18, surrounded by the annular seat 31 on which detachably rests the baffle ring 34 having the curved conical baille flange 35 depending, within said flange 30 of said frame 26, in close relation with the carbon holders. Referring to Fig. I- it may be observed that the construction and arrangement of said baille ring 34 is such as to form two annular dust chambers 37 and 38. Said chamber 37 is formed between said ring 34 and the base plate 9 and its depending portion 20, and said chamber 38 is formed between said ring 34 and the baille flange 30 of said canopy frame 26.

Sa1d canopy frame is detachably connected with said base plate by the clamping means including the hook lugs 40 on said base plate, spring bails 41 pivotally connected with said frame in the bearing lugs 42 of the latter, and the eccentrics 43 which are carried by said bails and provided with the handles 45 by which they may be turned when in engagement with said hook lugs 40 to detachably engage the latter; it being understood that said eccentrics are turned to afford the greatest space between them and the bearing lugs 42 in order to slip them over the hook lugs 40 and are then turned on the latter 'to the position shown in Fig. I so as to clamp said frame to said base plate under the spring pressure of said bails 41.

Said canopy frame 26 has two annular globe seats 47 and 48 to which the inner globe 49 and outer globe 50 are respectively tted in substantially air tight relation, the upper edges of said globes being ground fiat for that purpose. Said inner globe 49 has the metal shield 52 resting on the upwardly extending central indentation 53 at the bottom of said globe to protect the glass from hot cinders which drop from the arc, and, said shield is notched at its margin so as to spring into engagement with the bead 54 and prevent said shield from falling out when said globe is inverted. Said outer globe 50 has the spring retaining bead 55 and upwardly extending indentation 56 at the bottom thereof. The spring bail 58 is pivotally connected with the eyes 59 on said canopy frame 26, beneath the latter, and has the central roller member 61 arranged to detachably engage said indentation 56 in said outer globe 50 thus maintaining the latter tightly in contact with said seat 41 on the canopy frame 26 under the spring pressure of said bail 58.

Said outer globe 50 has the spiral spring 63 which is detachably held therein by the bead 55, so that it will not fall out when said globe is inverted, and has the member 64 arranged to detachably engage said indentation 53 in said inner globe 49, thus maintaining said inner globe tightly in contact with its seat 40 on said canopy frame 26.

It may be observed that by the construction and arrangement of the lamp members above described a substantially confined heated atmosphere is maintained within said inner globe 49, and a substantially conined heated atmosphere is maintained exterior to said inner globe; said exterior atmosphere being a layer of hot air around said inner globe 49 in the chamber 65 between the closely spaced globes 49 and 50.

It may be observed that by merely upturning the handles 45 from the position shown in Fig. I the clamps of which they are a part may be readily disengaged from the hook members 40 on the base plate 9, thus releasing and permitting the removal of the canopy frame 26 as shown in Fig. II. Moreover, it is to be understood that by merely turning the bail 58 aside so as to disengage the roller 61 from the outer globe 50 both globes may be removed and may be separated for cleaning as indicated in Fig. II. That is to say, all of the parts in which dust from the products of combustion may accumulate are readily removable and separable for cleaning, and may be as readily restored to their assembled position shown in Fig. I.

It is to be understood that when the lamp is operated with the parts in the assembled position shown` in Fig. I the inner globe 49 1s maintained at a temperature so high that the products of combustion within said globe 49 are not condensed on it and it thus remains clear.

Although I prefer to form said globes 49 and 50 as shown, to retain said shield 52 and spring 63, it is to be understood that -other forms of globes may be employed;

the essential feature of my invention, in this respect, being the provision of an inclosed arc lamp with means which during the operation of the lamp maintain the globe immediately surrounding the arc at a temperature sufliciently high to minimize and substantially prevent its obscuration by the deposit thereon of the products of combustion from the arc.

I do not desire to limit myself to the precise details of construction and arrangement herein set forth as it is obvious that various modiications may be made therein Without departing from the essential features of my invention as defined in the appended claim.

I claim In an arc lamp, a globe adapted to surround the arc, an outer globe uniformly spaced from the first globe to inclose a thin sheath of air therebetween, a canopy frame having a seat for each of said globes, a spring between the two globes at the lower part and a spring bail fastened to said canopy frame bearing against the lower part ot' said outer globe whereby both said globes are maintained against theirl seat on the canopy frame.

In testimony whereof, I have hereunto signed my name at Philadelphia, Pennsylvania, this sixteenth day of January, 1913.

THOMAS SPENCER. Witnesses:

GEORGE Tne'roN, ARTHUR E. Parels. 

